The definition of a hemodynamically significant ductus arteriosus

A cause and effect relationship between a hemodynamically significant ductus arteriosus (DA) in premature infants and important short- and long-term morbidities remains unproven. Over 60 randomized controlled trials (RCTs) of patent DA (PDA) treatment have failed to demonstrate a reduction in important neonatal adverse outcomes, including intraventricular hemorrhage (IVH), necrotizing enterocolitis (NEC), chronic lung disease (CLD), death or neurodisability.1 Although the PDA is a plausible trigger for many of these complications, consensus is elusive with the recognition that causality has not been proven from the RCTs and the PDA may just be a common occurrence in this population.